Characterization of CD19⁺ B cells in the lymph node suggests the cells resistant to removal are memory cells. Contour plots of cell subsets and MFI of CD38 on CD19⁺ cells from (A) iliac lymph nodes of controls, and (B) RTX-treated patients. Bar graphs of (C) lymph node CD27⁻IgD⁺CD19⁺ naïve B cells, (D) CD27⁺IgD⁺CD19⁺ memory B cells, (E) CD27^hiCD38^hiIgD⁻CD19⁺ plasma cells, (F) CD27⁺IgD⁻CD19⁺ memory B cells, and (G) CD27⁻IgD⁻CD19⁺ B cells. For all bar graphs, one symbol represents one individual, and the height of the bar represents the mean. (H) Detailed analysis of CD19^loCD20^lo cells alone in RTX-treated patients.